The present invention relates to a one-way clutch for use, for example, in automotive transmissions.
FIG. 20 is a sectional view showing a conventional one-way clutch assembly 100. The one-way clutch assembly 100 is typically employed by the automotive torque converter or the like as means for transmitting motive force only in one direction. In the figure, a synthetic-resin outer retainer 101 is press-fitted in an outer ring 50. Likewise, a synthetic-resin inner retainer 102 is press-fitted on an unillustrated inner ring.
FIG. 21 is a sectional view showing a state in which the one-way clutch 100 (only the outer retainer 101 is shown) is press-fitted in the outer ring 50. In this process, an edge 101a of an outermost part of the outer retainer 101 abuts against the outer ring 50, making it difficult to press-fit the outer retainer into the outer ring 50. Hence, it is not easy to assemble the one-way clutch 100 in the outer ring 50.
Aside from the above problem, the practical use of the one-way clutch assembly 100 involves the temperature elevation thereof, causing tensile stress in an inside circumferential surface of the outer retainer 101. In a few cases, this may result in the occurrence of cracks in the outer retainer 101.
In view of the foregoing, it is an object of the present invention to provide a one-way clutch easy to assemble in the outer ring. The present invention has another object to provide the one-way clutch adapted to prevent the occurrence of cracks in the outer retainer.
A one-way clutch according to the invention comprises:
sprags circumferentially arranged at predetermined space intervals,
an outer retainer and an inner retainer for respectively retaining an outer side and inner side of the sprags, and
A spring for biasing the sprags in one circumferential direction, wherein
(1) said outer retainer has a general annular form with a predetermined axial width and includes outwardly projected projections and pockets with said sprags inserted therethrough, said projections and pockets being alternately arranged in the circumferential direction, wherein an outermost part at each of said projections has its axially opposite side edges chamfered;
(2) said outer retainer and said projections are integrally made of resin material; and
(3) a contact width of said outermost part with an outer ring in an axial direction is greater than an open width of said pocket in an axial direction of said outer retainer.
According to the one-way clutch featured by the above item (1), the chamfered portions of the outer retainer abut against an inside edge of the outer ring when the outer retainer is press-fitted therein. Hence, the outer retainer is guided in a manner to bring its axis into accurate alignment with the axis of the outer ring. This provides for smooth press-fitting of the one-way clutch, facilitating the assembly thereof in the outer ring.
Further, the one-way clutch featured by the above items (2) and (3) ensures a sufficiently great axial contact width between the projection and the outer ring. Accordingly, the outer retainer does not suffer the great tensile stress in its inside circumferential surface even when the outer retainer is thermally expanded due to the evaluated temperature. As a result, the occurrence of cracks is prevented.